This is going to be my setup ITR Oversized Pistons in a GSR block with stock rods and gsr crank. The head is going to be a stock GSR head too. What do you think the compression ratio will be and will this setup run fine on the stock p72 ecu?

 

somewhere in the 10.7-10.9:1 neighborhood

Get some form of engine management, crome, hondata, etc.

 

So it wouldnt be a good idea to run that setup on stock p72 maps?

 

it'll run fine. just need to use 91 octane gas

 

i have a similar question to this..sorry for threadjacking but it relates to the question....if he's going ITR pistons in a gsr block...shouldn't he tune it right away when he starts it up, so it wont run lean or rich which would cause damage to the engine? so he'd have have it tuned before any driving on the streets, correct?

 

gsr with US type R pistons will work just fine on p72 ecu with no tuning.

Higher CR tends to use less gas anyway, the only time you might see trouble is if you have aftermarket cams on the car. type R CTR cams will work fine on p72 you need something more aggressive to cause you issues...

 

Thanks guys.

 

http://www.c-speedracing.com/h...c.php

USDM ITR ~ 10.9
JDM ITR ~ 11.4

that is with 81.25mm

 

hmm if ure gonna take out the block..
maybe get an LS block, ARP bolts in the LS rods, and oversized jdm itr pistons, and of course the ls/vtec kit.
keep your gsr shortblock as a spare, or sell it to work on the head.

 

kinda what the guy above me is saying but use the LS crank in the GSR block so u will maintain stock VTEC.

 

Not a option i'm buying a longblock already built with this setup.